This is a simple yet effective darkness activator. It uses an LDR to detect the light and when no light is present, it will sound an alarm from a cheap 8Ohm speaker. This circuit can be easily converted to a light detector by simply adding an inverting transistor driver at the output of the 555. This circuit performs a power failure alarm. It is a
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555 oscillator that is off due to the fact that voltage appears at pin 7. When the voltage at pin 7 fails to appear, the alarm will sound from the buzzer. This is a simple metronome circuit that is useful for the friends of music. It will generate the classic toc-toc sound like the mechanical metronomes. The period of the signs can be adjusted from the 250K potentiometer. generator, AKA Morse code generator. The circuit will generate the characteristic `beep` sound of the Morse code generators, every time the switch is pressed. The missing pulse detector is actually a one-shot device that is continuously re-triggered from the input pulse. The component values for the resistor and the capacitor are to be changed to fit your needs. You should select the parts so that the delay should be about 30-40% bigger than the period of the input pulses. If it is bigger than two input pulses, then in order to detect the input pulse, there must be at least two input pulses missing. This is a touch switch version of the 555 switch connected as monostable multivibrator. The 2N2222 shall perform an amplifier able to sense slight loads on the plate such as static electricity from the human body. A switch debouncer is a mid-stage block that will clear and square the signal from a push button or a switch. Those switches are very noisy and the output waveform is filled with noise that will generate false pulses, due to poor contact condition,...
This project fits more for custom made battery casing that can have more space to hide things inside. This switch with few alterations can be used for any other project as well but is designed based on e-bike needs! This project use a clever functionality of....
The circuit described here uses ultrasonic oscillations and operates based on the propagation velocity of these oscillations in the air. Thus, we can easily determine the distance of two points if the time within which the wave travels this distance is....
Sometimes the precious metals are hidden too deep and are not detected except with complicated devices. In many cases, however, small pieces of precious metal buried near the surface can be detected by relatively simple means. Everyone is very attractive to....
Many times for various reasons we forget or can not water the plants that we have in our homes. And many humidity sensors units just notify us with a beeping sound or with a flashing light, that the pot needs watering. But what if we are away from home? This....
The principle behind a metal detector is really very simple. Proof of this is the circuit that follows, in which it proves that the construction of a metal detector can be done in the minute, with few components that we find very easily everywhere. With the....
The sub-harmonic bass generator is a sound producing unit for guitars. The sound it produces looks very much like that of the bass guitar. The octave generator is sometimes quite unusual since it does not produce any of the usual ways of coloring the sound,....
In the past the sounding (sea bottom measurement) was done with the "bullet", that is, with a heavy lead object that the seamen plucked into the sea hung from a calibrated rope. As soon as the "bullet" reached the bottom, the depth appeared directly from the....
This Amplifier was designed to have the following specifications: Distortion less than 0.1% at full power of 100W even at 20KHz. Power has to be attributed to an extended bandwidth. The output transistors must be protected against short circuits. The power....
A series of LEDs serve to alert the gardener when plants need water. Using two conventional digital integrated LEDs and a series of LEDs, we make a very useful device for gardening. The device detects the amount of water in the pot and alerts the grower.....
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